Sodium xylenesulfonate (or its ammonium cousin) are hydrotropes -- organic compounds that increase the ability of water to dissolve other molecules.
Xylenesulfonates are used in detergents and shampoos in amounts of up to 10% of the product.
They are surfactants, but they are usually added to thicken a mixture like shampoo, and to help keep some other ingredients in solution. This makes the product clear or transparent, as the cloudy precipitates are put back into solution.
ammonium xylenesulfonate: InChI=1/C8H10O3S.H3N/c1-6-3-4-8(7(2)5-6)12(9,10)11;/h3-5H,1-2H3,(H,9,10,11);1H3/fC8H9O3S.H4N/h;1H/q-1;+1
sodium dimethylbenzenesulfonate: InChI=1/C8H10O3S.Na/c1-6-3-4-8(5-7(6)2)12(9,10)11;/h3-5H,1-2H3,(H,9,10,11);/q;+1/p-1/fC8H9O3S.Na/q-1;m